Benzene carboxylic acids alkylated in the nucleus and process of preparing them



Patented MarQ ZG,

i v BENZENE oAnBo 2,195,198 c b xYLIc A IDSALKYLATED IN THE NUCLEUSAND'PROJCESS PRE- TARIN'G fr'HEM I Gerhard Balle andI-Iermann Wagner,Frankfort-' on-the-Main,

and ,Eberhard Nold, Ludwigs-' haf en-on-the lthine, Germany; assignorsto *I. G. Farben'indus'trie Aktiengesellschaizt,- H Frankfort-on-tlieMain, Germany Y No Drawing. Application June's, 1938, Serial Nor I212,124. In Germany June,7, 1937 4Claims. (c1. zoo-e515) The-presentinvention relates to benzene carboxylic, acids alkylated in'the nucleusand to a process of preparing them;

Attempts to introduce yet been unsuccessful. i

I having at least four carbon atoms, with ally-1 -'15 We have found thacorresponding acetophenones or omega haloe genacetophen'ones', which aresubstituted in the nucleus by one or several aliphatic orcyclo-'.,

aliphatic hydrocarbon radicals having, together at least eight carbonatoms and one of which pohalogenite solution, that are solutions ofsalts of, for instance, hypochlorous or .hypobromous acid, to form'thecorresponding benzene car boxylic acids, the hydrocarbon radicalspresent l as side chains beingpractically unattack'edsw The substitutedacetophenones or omega halogenacetophenones are obtained inknownmanner-by condensing an acetic acid halide on. halogen-acetic acidhalide :with a substituted.

hydrocarbon of the benzene series. Examples of the latter are thehomologous alkyl benzenes obtained by catalytic reduction of thearaliphatic ketones which are obtainable from hydrocarbons of thebenzene series and higher fatty acid halides; furthermore, condensationproducts of benzene hydrocarbons with higher aliphatic or-cycloaliphatic olefines, alkyl'halides andchloring ationproductsobtained from hydrocarbon mixtures containing hydroaromatichydrocarbons as they are obtained in the hydrogenationof coal and thelike. b i

The oxidation of the substituted acetophonones oromega-halogen-acetophenones is preferably carried out in a dilutesolution .at temperatures" comprising room temperature up to about 100preferably at 70 C. to 80 C;,'- s o= that at; least part of thecarboxylic acid salt obtained passes into solution. It is not necessaryto start from pure (distilled) acetophen'one derivatives oromega-halogen-acetophenone derivatives. When using crude darkcondensation products with acetic acid halide 01'- halogenacetic acidhalide (if desired, after the elimination of the unchanged startingmaterials and of by-products having a low boiling point) it is advisableto work with an excess of hypohalogenite solution by which the darkproducts are bleached and only slightly colored carboxylic acid saltsare obtained. The oxidation of the omega-halogenacetophenones proceedsmore rapidly and more smoothly than that of thenon-halogenateddedirectly alkyl groups. l into benzoic acid or ahomologue thereof have as v tobenzene carboxylic acids are obtainable ina" good yield by oxidizingthe 1 rivatives. from the solutionof theirsalts by acidifying with dissolving them in alkalies; by evaporation anddrying the salts are obtained in theform of white to. light-brownpowders.

The benzene carboxylic acidsv or the salts thereof thus obtained,particularly those containing as substituents hydrocarbon radicals of atleast twelve carbon atoms, are soap-like prodacts and may be usedinstead of 'soa'ps'or as ad-v ditions to soaps.' The products arelikewise valuable intermediate products for thefpreparation of textileadjuvants and the like Y The following examples "serve to illustrate theinvention, but they are not intended to limit it thereto, thefparts'being byiweight and the ratio of parts by volumeand partsbyweight is that-2d (l) lAmixtu're of 33 parts of acetyl chloride and100 parts of n-dodecylbenzene,. obtained by catalytic reduction oflaurophenoneare {introduce'dlinto a'sus'pen'sion of 154parts ofaluminium hich exists between the liter and the kilo:

chloride (anhydrous) in1about200 parts of car- The 'carboxylic acids areprecipitated mineral acid or. acetic acid, separatedv from the I liquidand, if; desired, reconverted into salts by bon, tetrachloride, whilecooling and stirring;

after some hours the whole ispoured'on ice,

worked up cent., meltingpoint 4891C). v

100 parts of n'.-dodecylacetoph'enone are. gradually introduced 'atabout C to, '8,0 C. into 2550.parts by" volume of a sodium hypochloritesolution of 3 per cent. strength orjthe; equivalent quantity of.potassium hypochlorite solution and,

stirred at thisutemperatureuntil atestportion An excess of hy.. presentis decomposed The n-dodecylbenzoic has become soluble in water.pochlorite which may be with the aid of bisulfite.

acid is separatedin the'form of asolid product ",inthe usual manner anddistilled" underl reduced" pressure. (Yield 70 00 .75 per i t which-gasregardsits "appearance; resembles the fattyacids, by acidifying it withdilute mineral acid or acetic .acid. After washing with water theproduct is dissolved in the calculated amount of hot dilutesodiumcarbonate solution or caustic soda solution; after evaporation thesodiumparadodecylb-enzoate is obtained in the form of a white-powder;The yield amounts to per cent.

Small amounts of unchanged parent material may be removed with the aidof-solvents, for instance, petroleum ether. The sodium salt producessoap-like solutions; the product is; however, sparingly soluble in coldwater. The calcium salts and barium salts as well as the heavy metalsalts are very sparingly soluble in water.

The free acid is soluble in organic solvents. for instance, in benzenehydrocarbons, halogen hydrocarbons, and alcohols. v

(2) To a suspension of. 53, parts of aluminium chloride (anhydrous) inabout 300 parts of carbon tetrachloride there is added, while stirringbelow +10 C., a mixture of i l parts of ch1or= acetyl chloride and 100-parts of alkyl benzene (molecular weight about 260, corresponding to anaverage chainlength of the alkyl substituents of. Bio 14 C-atoms)obtained by condensation of benzene with a chlorination product of ahydrocarbon mixture, containing hydroaromatic compounds and boilingunder a pressure of 20 mm.

mercury at 50 C. to 125 C., as it is obtained in the hydrogenation oflignite. After a subsequent stirring for 12 hoursthe whole is poured onice at room temperature. After washing and drying the condensationproduct the readily volatile by-products are distilled up to a boilingpoint of about 130C. under a mercurial pressure of 6' mm. 112 parts ofthis crude alkylated omega-chloracetophenone are introduced at about 80C. into 2509 parts of an industrial sodium hypochlorite solution of 3per cent.

strength and kept at this temperature until the hypochlorite has beenconsumed. Thereactiou is promoted byxadding a small quantity of sodiumsalt of the corresponding alkyl bcnzoic acids to the 'hypochloritesolution as emulsifying agent. After addition of some animal charcoalthe whole is filtered hot froinsmail amounts of resinous by-products andlay-acidifying the light brown filtrate there is obtained a mixture .ofalkylated ,benzoic acids (average molecular weight about 390,corresponding to an average chain length of the alkyl substituents of,13 to 14 C-atoms) in the form of a massresembling resinicacid andcapable of being-pulverized at temperatures below. 1+10 C., but viscouswhen j hot. If desired, this mass is dissolved in dilute alkali and thesalts are obtained in'the form of a light-brown powder having propertiesresembling those of resin soaps. (Theyield amounts to 105 parts.)

(3) Tea mixture containing 100 partsof fdi-. tertiary-butylbenzene,about 200, parts of carbon tetrachloride and 60 parts ofchloracetylchloride. there are' gradually introduced below +10C.,

while stirring, parts ofanhydrous'aluminium chloride; the whole issubsequently stirred for several hoursat about 25 C., poured on ice andworked up, in the usual manner. parts of a condensation product freedfrom more "easily boiling portions by distillation toa boiling point tof about C. under a pressureof 5 mm. areoxidised (as described inExample 1) with 2000 parts of a sodiumhypochlorite solutionofB per cent.strength or the" equivalent amount of so..

dium hyprobromite solution and worked up.-

The sodium'salt of the di-tertiary-butylbenzenecarboxylic acidisobtained in the form of awhite powder in a yield of about 70 per cent.of the amount calculated for the di-tertiary-butylbenzene used. 7

The free acid is prepared from'the salts as indicated above. The crudeproduct contains as impurities alkylbenzoic acids which are formed bythe alkyl radical in the di-tertiary-butylbenzene being split ofi by theinfluence of aluminium chloride; after recrystallization from methanolthe di-tertiary butylbenzoic acid melts at 128C. I

(4) To a mixture from 400 parts-of the alkyl benzene mixture, obtainedby condensation of diisohexylene and benzene by means of boron Ifluoride-phosphoric, acid and distillation of the easily boilingportions up toa boiling point at 110 C. under a mercurial pressure of 15mm. (molecular weight 213), about 200 parts ofcarbon tetrachloride and100parts of bromacetylbromide; there are gradually introduced, whilestirring, below ,+10 C. 65 parts of aluminium chloride (anhydrous). Thewhole is stirred for several hours at about 25 C., poured on ice andworked up in the usual manner 100 parts of the condensation productfreedfrom, the easily boiling portionsby distillation up to a boiling pointofabout -C. under a mercurial pressure of.3'mm. are oxidized with 1900parts of sodium phyochloritesolution of' 3 per cent. strength or theequivalent amount of a potassium hypobromite solution (as, indicated'in'Example 1) and worked up., By acidifying with mineral acid or aceticacid a mixture of alkyl benzoic acidshaving an acid number of about 230is obtained in the form of a brownish partly solid mass. The alkali or.ammonium 'saltsof this acid mixture yield foaming aqueous solutions. Thesalts of alkaline-earth metals and heavy metals are difilcultly solublein water even in the warmth.

We claim:

1.v The n-dodecylben zoicacid which is soluble in benzenehydrocarbon,halogenv hydrocarbons and alcohols and the sodium salt': of which beinga white powder soluble in water to a soap-like solutiomwhereas' itssalts of calcium, barium and of the heavy metals are diflicultly'solublein water. 1

2. The benzoic acid of the formula: I

R standing for saturated hydrocarbon radicals of 13 to 14 carbon atoms,beinga resinic acid- 4. A mixture of alkyl. benzoic acids having an acidnumber of about 230'andbeine, a brownish partly solid mass.

.GERHARD- .BALLE, HERMANN WAGNER, EBERHARD NOLD.

